The present invention provides highly effective materials and methods for applying treatments to animals. In a specific embodiment, the invention relates to controlling populations of internal and external pests that attack livestock, deer, and other domestic and wild animals.
Treating livestock and game animals to control ticks, biting flies, and similar haematophagous or noxious arthropods or other parasitic pests is essential to prevent major economic losses. Typically, these parasites pierce the skin of animals, causing damage to the hides, blood loss, and irritation, as well as transmission of deadly infectious diseases. These factors contribute to the enormous economic losses sustained by the livestock industry. Losses in livestock production (cattle, sheep, swine, and poultry) in the U.S. due to arthropod pests have been estimated at more than $3 billion. This figure does not include the cost of pest control or losses to the equine industry (Drummond, R. O., J. E. George, S. E. Kunz [1988] Control of Arthropod Press of Livestock: a Review of Technology, CRC Press, Inc., Boca Raton, Fla., 245 pp.). Although precise figures for most countries are lacking, estimates of world-wide economic losses due to ticks and tick-borne diseases alone are in the billions of dollars.
Bovine parasitism is the source of some of the most severe economic losses encountered by cattle producers in the United States. Cattle are infected by internal and external parasites that range from brown stomach worm (the most common) to lungworm, mites, ticks, and lice.
Ticks affect approximately 800 million cattle and a similar number of sheep throughout the world (Sutherst, R. W., R. J. Jones, H. J. Schnitzerling [1982] Nature (London) 295:320-322). McCosker (McCosker, P. J. [1979] xe2x80x9cGlobal aspects of the management and control of ticks of veterinary importance,xe2x80x9d In Recent Adv. Acarology, Rodriguez, J. D. (ed.), 2:45-53) estimated the world-wide impact of tick-borne diseases of cattle at approximately $7 billion. In addition to transmission of diseases, ticks cause severe damage due to failure of cattle to achieve expected weight gains and damage to hides to be used for leather. According to Norval (Norval, R. A. I. [1990] Parasitologia 32:155-163), weight losses in cattle are estimated at 4.4 grams per Rhipicephalus appendiculatus female and 10 grams per Amblyomma hebraeum female. Estimates of losses in wildlife are unavailable; however, tick infestations of white-tailed deer (Odocoileus virginianus) in some areas are so severe that they have been reported to kill fawns (Drummond et al., supra).
Internal parasites are also a major economic and health problem. Nearly all vertebrates and many invertebrates are affected by internal parasites, for example, the Platyhelminthes and filarial worms.
Treatment or prevention of internal parasite, insect, and tick infestations in animals, especially animals in the wild, is a formidable task. Thus, it is not surprising that no single, universally accepted method is available for this purpose. Common practices for delivering a pesticide, e.g., an insecticide or an acaricide, to livestock include (1) direct, whole-body treatment, where the animal""s body is drenched with pesticide-containing liquids; (2) systemics, where the pesticide is allowed to circulate in the host""s blood; and (3) controlled-release systems, which are usually physically attached to the animal and which release pesticide continuously over a period of weeks or months.
There are disadvantageous features to all of these previously described methods. Whole body treatments involve substantial waste. In addition, for dipping or spraying, the animals must be herded and driven to, or through, the treatment area. Such procedures are both labor-intensive and stressful to the livestock. Moreover, due to the high potential for spillage, these operations pose significant environmental hazards for the surrounding area as well as health hazards for workers.
Systemics are generally not acceptable, especially for food animals, because of the toxic residues that can concentrate and remain in animal tissues for extended periods. Controlled-release devices, e.g., ear tags, risk infection or skin irritation when these devices are attached to the animal""s body. None of these procedures are suitable for use with wildlife such as deer or other large herbivores.
Common methods of administering anthelmintics include injection and oral administration. The disadvantage of injectable formulations of anthelmintics include unwanted side effects and injection site blemishes that can reduce meat""s marketability. Oral formulations are, at best, impractical in the case of large herds of domestic animals and unfeasible in the case of wild animals such as deer.
An alternative to the methods described above is self-medication. In self-medication methods, an animal which is attracted to a device that offers a bait, e.g, food, materials for nest construction, etc., is sprayed or coated with pesticide-containing composition when the animal either contacts the device or in some way triggers the device to release the pesticide. Such methods offer an advantage over the previously described methods by minimizing the amounts of pesticide dispersed to the host and, consequently, into the environment.
One well-known example of a self-medicating device is the Duncan Applicator (ARIPO Patent No. AP/88/00079), which has been used to treat livestock and wild ungulates in Africa. The Duncan Applicator consists of a container placed on top of a tall, threaded rod which is placed in a bin containing feed. The overhead container releases an oily liquid pesticide mixture which slowly flows down the rod. When the animals place their heads in the bin to eat the feed, they touch the rod and receive a small amount of pesticide. The Duncan Applicator, due to its design, has limited utility for treating livestock and most wildlife. A principal disadvantage of the Duncan Applicator device is that the container at the top of the threaded rod is small and is exhausted in a short period of time, usually requiring the device to be recharged every day. Such high incidence of maintenance makes the Duncan Applicator difficult to use in areas which may be inconvenient to reach or inaccessible under inclement weather conditions. Further, daily recharging of the Duncan Applicator incurs a high labor cost, making the cost of using the device unattractive. Substituting a larger capacity container on the Duncan Applicator would not provide a complete remedy to the disadvantage of high maintenance. A larger capacity container would increase the tendency for the Duncan Applicator to tip over. If the device is tipped over, the result is a spill of the pesticide on the ground contaminating the environment. The Duncan Applicator poses an environmental threat since the pesticide is not contained and may easily be spilled if the Applicator is knocked over. Two scientific articles have been published relating to this Applicator (Duncan, I. M. (1992) xe2x80x9cTick control on cattle with flumethrin pour-on through a Duncan applicator,xe2x80x9d J.S. Afr. Vet. Assoc. 63:125-127 and Duncan, I. M., N. Monks (1992) xe2x80x9cTick control on eland (Taurotragus oryx) and buffalo (Syncerus caffer) with flumethrin 1% pour-on through a Duncan applicator,xe2x80x9d J.S Afr. Vet. Assoc. 63:7-10).
Other variations of self-medicating devices have also been described. U.S. Pat. No. 3,870,023 describes an insecticide applicator for livestock which utilizes a wind-powered spray device. This clearly is distinguished from the subject invention, which does not use a spraying device to apply insecticide. Nor does the subject invention rely on wind power to dispense insecticide.
Other combination feeder/applicators include the inventions described in U.S. Pat. Nos. 3,137,274, 3,187,772, 3,941,096, 4,023,533, and 4,459,942. Each of these patents discloses a feeder to attract livestock and a means for dispensing insecticide which is operable when contacted by the animal. However, none of these patents describe a device which incorporates the elements of the subject invention.
U.S. Pat. No. 3,118,427 describes a xe2x80x9cbunt bagxe2x80x9d which dispenses liquid insecticide when the bag is contacted by an animal. The ""427 device essentially uses an absorbent material to surround the liquid pesticide storage area. U.S. Pat. No. 3,159,144 uses gravity to transfer insecticide from a cable or chain core, saturated with pesticide, to absorbent discs which surround the core. These devices also have limited container capacity and require frequent maintenance.
The livestock oiler disclosed in U.S. Pat. No. 3,727,586 also dispenses insecticide when the animal contacts the device. The ""586 patent employs a container which supplies pesticide by gravity to valves which open to dispense insecticide upon contact or rubbing of the valves by the animal. The apparatuses disclosed in U.S. Pat. No. 5,027,747 pertain to the use of absorbent wicks which contact an animal as it passes through a pathway.
The USDA/ARS has patented an apparatus for topical pesticide treatment of wildlife (U.S. Pat. No 5,367,983). This device consists of four columns around two feed bins. The pesticide is stored in a container in the center of the unit, adding weight to an already substantially unwieldy contraption which is too heavy to be manually lifted.
U.S. Pat. No. 5,357,902 pertains to the UF self-medicating applicator of Norval, Meltzer, Sonenshine and Burridge. This applicator contains a container for pesticide storage as opposed to the disposable, self-contained column of the subject invention which allows facile, effortless recharging with treatment material. This applicator is the subject of the following scientific article: Sonenshine, D. E., Allan, S. A., Norval, R. A. I. and Burridge, M. J. (1996) xe2x80x9cA self-medicating applicator for control of ticks on deer,xe2x80x9d Med. Vet. Entomol. 10:149-154.
It is therefore an object of the subject invention to provide an efficient, low-maintenance self-medicating applicator for wild animals and livestock, e.g., cattle, wild deer, etc. The applicator of the subject invention can store an amount of a treatment sufficient to make the applicator maintenance-free for several days, weeks, or months, and dispense a treatment externally to an animal in such a manner as to treat the animal. The invention can be used to deter or kill dangerous, disease-transmitting ticks and other biting insects and to kill internal parasites. As used herein, reference to xe2x80x9ctreatmentxe2x80x9d includes any pesticide, anthelmintic, medicament, lotion, repellant, or other composition which is to be applied to an animal. As used herein, reference to xe2x80x9cpesticidexe2x80x9d includes chemical pesticides or anthelmintics, as well as entomopathic fungi, nematodes, and bacteria, and compounds such as repellants and growth regulators.
The subject invention pertains to unique methods and devices useful for applying treatments to animals. In one embodiment, the subject invention provides devices which can be used to effectively apply pesticides, including anthelmintics, to animals. Advantageously, the devices of the subject invention can be used in remote locations to apply liquids to livestock or wild animals. Preferably, the liquid can be a composition comprising any treatment which is applied to an animal.
In a preferred embodiment, the device of the subject invention comprises a housing which can hold a liquid or a liquid container. The housing can be constructed of high density polyethylene, PVC, treated cardboard, or other sturdy, non-corrosive and non-biodegradable material. In one embodiment, the housing is surrounded by an absorbent material through which a liquid can move and be transferred to an animal. Upon placing the liquid container into the housing portion of the subject invention, the liquid container is punctured, or otherwise opened, thereby allowing the liquid to flow from the container. The liquid then travels to the absorbent material where the liquid spreads through the absorbent material and can be transferred to an animal which contacts the material.
In an additional embodiment, the housing is itself sufficiently porous to permit a liquid to permeate through from an inner cavity to an outer surface where an animal can contact the outer surface and the treatment. In this embodiment, the treatment may be poured directly into the housing, or the treatment may be introduced into the housing in a container which is, for example, then punctured. The housing may be mounted vertically, horizontally, or in any other appropriate orientation.
Animals can be attracted to the device of the subject invention by a suitable attractant and, while contacting the attractant, they are treated passively by contact with the outer surface. In one embodiment the device of the subject invention has an animal attractant receptacle which holds, for example, food, materials for nest construction, pheromonal preparations, other attractants, or the like, strategically disposed in relation to the housing so that an animal, while obtaining a bait therefrom, will necessarily contact the absorbent material and thus apply to itself the liquid. As the liquid formulation preferably comprises an active ingredient for treating the animal, the animal thus becomes treated with an appropriate medicament each time it contacts the absorbent material. In this manner, the animal is treated regularly and, advantageously, without the undesired stress of human handling, or the expense of dipping stations, spraying equipment, and related facilities.
In a specific embodiment, the device of the subject invention consists of a column which has a weather guard attached to the top and an animal attractant at the bottom. In another embodiment, the device is mounted horizontally at, for example, the edge of a feed bin such that animals which come to feed contact the device as they access the feed. This embodiment can utilize a porous housing such as high density polyethylene, wherein the treatment is poured or flows in the housing and then wicks to the outer surface of the housing. In a preferred embodiment, the animal attractant is contained within an animal attractant receptacle. The device can be attached to any suitable structure (e.g., buildings, trees, fence posts), or it can be free standing. In one embodiment, the weather guard and attractant receptacle can be cone shaped and can act as the attachment points for installation of the invention.
In one embodiment, the housing is a hollow tube, the upper portion of which is adapted to contain the treatment to be applied to the animal. The treatment can be contained in the upper portion of the column in a container which is activated at the time of installation. At the time of installation, the container can be ruptured by an activation mechanism. In one embodiment, the activation mechanism is contained at the base of the upper portion or within the lower portion of the column. The treatment will then flow to the absorbent material or will pass through a porous housing. The column will be saturated both by using the force of gravity to draw the treatment down the lower portion of the absorbent material or porous housing and by the wicking action of the absorbent material or porous housing to draw the treatment up the upper portion of the device. The treatment and activation mechanism can be separated by a simple bulkhead inside the housing.
Upon complete utilization of the treatment, the liquid container can be removed and replaced with a new container. Alternatively, additional fluid can flow, or be poured, into the cavity in the housing. If a container is used, the empty container can be recycled or otherwise disposed of in an appropriate manner.
If the device of the subject invention is designed as a column, the column can be specifically constructed to fit onto the column supports of other applicators. In this way, the self-contained treatment columns can replace the original columns, thereby allowing the treatment containers to be eliminated and consequently reducing possible environmental contamination. After weeks of treatment with the other applicators, only the spent column would need to be disposed of and replaced.
The subject invention further concerns a method for delivering a treatment, whereby the method employs the novel applicator device as described herein. More specifically, the method comprises placing the novel applicator device in an area accessible to the animal to be treated and supplying the applicator with a bait, e.g., feed, and an appropriate treatment composition.
This invention is unique and advantageous because it is light-weight and can be made portable, with a self-contained treatment component, and can easily be transported by one person. Also, the subject invention is efficient, low maintenance, environmentally sound and easy to use.